Is 650W enough for an RX 6800 XT + Ryzen 5 5600?
Yes on an ATX 3.x unit — risky on older PSUs.
- noteSustained load: 446 W (Ryzen 5 5600 76 W power-limit budget + Radeon RX 6800 XT 295 W measured gaming + 75 W rest of system) = 69% of a 650 W unit.
- goodSustained load is a comfortable 69% of 650 W.
- cautionRadeon RX 6800 XT's measured spikes push total demand to 718 W for milliseconds — above the unit's 650 W rating. An ATX 3.0/3.1 unit is built to ride that out (rated for excursions to 1300 W); an older unit may shut down mid-game. This is exactly the case TDP-only calculators miss.
The math, with sources
- GPU sustained draw: 295 W — Radeon RX 6800 XT measured while gaming (TechPowerUp — GeForce RTX 5050 review, Power Consumption charts (July 2025 test suite)) — its rated board power is 300 W.
- GPU transient spikes: 567 W — Radeon RX 6800 XT spikes to ~567 W for milliseconds (TechPowerUp — GeForce RTX 5050 review, Power Consumption charts (July 2025 test suite)). Spikes trip older PSUs that averages never show.
- CPU power budget: 76 W — Ryzen 5 5600 budgeted at its official turbo power limit (AMD spec sheet — official TDP + PPT socket power limit; budgeted at the PPT limit (no bench chart read for this part)). No bench chart was read for this part, so the calculator uses the vendor's own ceiling — the real peak sits at or below it.
- Rest of the system: 75 W — Motherboard, RAM, drives, fans and USB devices — a fixed allowance.
- Sustained total: 446 W — 76 + 295 + 75 = 446 W of steady load.
- With 15% headroom: 513 W — Sustained x 1.15 — margin for capacitor aging, heat, and staying near the efficiency sweet spot. (The sustained figure is already conservative: CPU all-core peak and GPU gaming peak rarely coincide.)
- Spike check: 718 W — CPU peak + GPU spike + rest = 718 W for milliseconds. The recommendation also covers this outright, so even a pre-ATX-3.0 unit is not spike-tripped.
- Recommended: 750 W — The smallest standard size covering both 513 W (sustained + headroom) and 718 W (spike total).
Measured numbers from
- Radeon RX 6800 XT: TechPowerUp — GeForce RTX 5050 review, Power Consumption charts (July 2025 test suite)
- Ryzen 5 5600: AMD spec sheet — official TDP + PPT socket power limit; budgeted at the PPT limit (no bench chart read for this part) (no stable link)
AFFILIATE_SLOT: tested 750W ATX 3.x unit picks will be listed here. No links yet — added only once real recommendations exist.